diff options
| -rw-r--r-- | library/listbox.tcl | 162 |
1 files changed, 128 insertions, 34 deletions
diff --git a/library/listbox.tcl b/library/listbox.tcl index 17c03c0..9c4317a 100644 --- a/library/listbox.tcl +++ b/library/listbox.tcl @@ -243,18 +243,25 @@ if {"x11" eq [tk windowingsystem]} { proc ::tk::ListboxBeginSelect {w el {focus 1}} { variable ::tk::Priv - if {[$w cget -selectmode] eq "multiple"} { + if {[string equal [$w cget -selectmode] "multiple"]} { if {[$w selection includes $el]} { $w selection clear $el } else { $w selection set $el } } else { - $w selection clear 0 end - $w selection set $el - $w selection anchor $el - set Priv(listboxSelection) {} - set Priv(listboxPrev) $el + $w selection anchor $el + set Priv(listboxPrev) $el + if {[$w selection includes $el]} { + # Deselect two separate ranges adjacent to $el, + # in order to prevent display flicker of $el. + $w selection clear 0 [incr el -1] + $w selection clear [incr el 2] end + } else { + $w selection clear 0 end + $w selection set $el + } + set Priv(listboxSelection) {} } tk::FireListboxSelectEvent $w # check existence as ListboxSelect may destroy us @@ -287,34 +294,121 @@ proc ::tk::ListboxMotion {w el} { tk::FireListboxSelectEvent $w } extended { - set i $Priv(listboxPrev) - if {$i eq ""} { - set i $el - $w selection set $el - } - if {[$w selection includes anchor]} { - $w selection clear $i $el - $w selection set anchor $el - } else { - $w selection clear $i $el - $w selection clear anchor $el - } - if {![info exists Priv(listboxSelection)]} { - set Priv(listboxSelection) [$w curselection] - } - while {($i < $el) && ($i < $anchor)} { - if {[lsearch $Priv(listboxSelection) $i] >= 0} { - $w selection set $i - } - incr i - } - while {($i > $el) && ($i > $anchor)} { - if {[lsearch $Priv(listboxSelection) $i] >= 0} { - $w selection set $i - } - incr i -1 - } - set Priv(listboxPrev) $el + set p $Priv(listboxPrev) + if {[string equal {} $p]} { + # There is no previous element. + # Set it to the current element. + $w selection set anchor $el + if {![info exists Priv(listboxSelection)]} { + set Priv(listboxSelection) [$w curselection] + } + set Priv(listboxPrev) $el + tk::FireListboxSelectEvent $w + return + } + + # Determine the index ranges to select and deselect + set Priv(listboxPrev) $el + set a [$w index anchor] + if {$el > $a} { + if {$p <= $el} { + if {$p < $a} { + # p<a<el + set deselectRange(0) [list $p [incr a -1]] + set selectRange [list [incr a 2] $el] + } else { + # a<p<el + set selectRange [list [incr p] $el] + } + } else { + # a<el<p + set deselectRange(0) [list [incr el] $p] + } + } elseif {$el < $a} { + if {$p >= $el} { + if {$p > $a} { + # el<a<p + set deselectRange(0) [list [incr a] $p] + set selectRange [list $el [incr a -2]] + } else { + # a<p<el + set selectRange [list $el [incr p -1]] + } + } else { + # p<el<a + set deselectRange(0) [list $p [incr el -1]] + } + } else { + if {$p > $a} { + # el=a<p + set deselectRange(0) [list [incr a] $p] + } else { + # p<=a=el + set deselectRange(0) [list $p [incr a -1]] + } + } + + # Correct the selection and deselection range for items + # that existed in a previous selection. + if {[info exists Priv(listboxSelection)] } { + set i 0 + foreach index $Priv(listboxSelection) { + # deselectRange($i) may have been unset in a previous iteration + if {[info exists deselectRange($i)]} { + # We do a detailed inspection of the deselectRange to + # exclude all unwanted deselections. This may result in + # several contiguous deselectRanges that are not adjacent. + set begin [lindex $deselectRange($i) 0] + set end [lindex $deselectRange($i) 1] + if {($index >= $begin) && ($index <= $end)} { + # adjust deselectRange($i) + if {$begin == $end} { + unset deselectRange($i) + } elseif {$index == $begin} { + set deselectRange($i) [list [incr begin] $end] + } elseif {$index == $end} { + set deselectRange($i) [list $begin [incr end -1]] + } else { + # Split the deselectRange into two separate ranges, + # each being contiguous. The range with the higher + # index values will be subject to inspection in + # the next iteration + set deselectRange($i) [list $begin [incr index -1]] + set deselectRange([incr i]) [list [incr index 2] $end] + } + } + } + + # We do a course inspection of the selectRange up to the + # level where we can decide whether adjustment leaves us + # with anything to select. More detailed inspection doesn't + # gain much/any performance. + if {[info exists selectRange]} { + set begin [lindex $selectRange 0] + set end [lindex $selectRange 1] + if {($index >= $begin) && ($index <= $end)} { + if {$begin == $end} { + unset selectRange + } + } + } + } + } + + # deselect the items in each contiguous deselection range + foreach i [array names deselectRange] { + $w selection clear [lindex $deselectRange($i) 0] \ + [lindex $deselectRange($i) 1] + } + # select the items in the selectRange + if {[info exists selectRange]} { + $w selection set anchor $el + } + + if {![info exists Priv(listboxSelection)]} { + set Priv(listboxSelection) [$w curselection] + } + tk::FireListboxSelectEvent $w } } |